The subclass Euechinoidea includes almost all living species of sea urchin, with fossil forms going back as far as the Triassic.
Subclass
via
The subclass Euechinoidea includes almost all living species of sea urchin, with fossil forms going back as far as the Triassic.
== Taxonomy == List of orders according to World Register of Marine Species: Infraclass Acroechinoidea Order Aspidodiadematoida Order Diadematoida Order Micropygoida Order Pedinoida Infraclass Carinacea Superorder Calycina Order Phymosomatoida† Superorder Echinacea Order Arbacioida Order Camarodonta Order Salenioida Order Stomopneustoida Order Echinothurioida Infraclass Irregularia Superorder Atelostomata Order Holasteroida Order Spatangoida Order Echinoneoida Order Holectypoida† Superorder Neognathostomata Order Cassiduloida Order Clypeasteroida Order Echinolampadoida Order Nucleolitidae†
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).